Gulf carriers in general share that reputation for bad working conditions for crews and bad safety practices.
Your safest choice is a US or EU legacy carrier. But for example in Asia you will not have that choice for local routes. Then there aren't that many things you can see on the outside. But one thing that can help is going with a large airline that also operates long haul flights into the US and Europe. There is a list for example of airlines banned from operating into Europe. You get on that list by having questionable safety or maintenance practices. So being allowed to operate flights to Europe is a small positive signal.
Yes Gulf carriers, but not all of them, Emirates and Qatar are the most important.
They really have high standard and try their best to have the best safety standars. Is not for lack of trying. Is that their system has gome far too much in one direction that is now backfiring.
Absolutely you may have an airline that allows too much manual flying and too low procedure standars (it is what happened at first in commercial aviation). There is a sweet spot between standart procedure and manual proficiency, and some airlines have been going way beyond that spot for some time.
Your safest choice is a US or EU legacy carrier. But for example in Asia you will not have that choice for local routes. Then there aren't that many things you can see on the outside. But one thing that can help is going with a large airline that also operates long haul flights into the US and Europe. There is a list for example of airlines banned from operating into Europe. You get on that list by having questionable safety or maintenance practices. So being allowed to operate flights to Europe is a small positive signal.